In a Long Term Evolution (LTE) network, time-frequency resources are allocated to a terminal by using a transmission time interval (TTI) as a unit. In other words, the terminal is scheduled at a period of a TTI. This scheduling mode is referred to as a TTI scheduling mode, and is a conventional scheduling mode. In different network configurations, values of a TTI may be different in terms of time. Usually, one TTI is equal to one millisecond (ms) in terms of time. In an LTE frequency division duplex (FDD) network, duration from a time point at which a base station sends data to a terminal to a time point at which the terminal feeds back a response is 8 ms. In other words, there is a delay of 8 ms from a time point at which the base station sends the data to a time point at which the base station learns whether the data is successfully sent.
With popularization of LTE networks, various services such as high-definition videos and virtual reality develop rapidly. Emergence of these services imposes requirements for higher bandwidth and lower delays on the LTE networks. In an LTE network, one subframe in a time domain corresponds to one TI, one subframe consists of two timeslots (slot), and each timeslot occupies 0.5 ms. One timeslot consists of a plurality of symbols (symbol). When a normal cyclic prefix is configured, one timeslot includes seven symbols, and when an extended cyclic prefix is configured, one timeslot includes six symbols. In view of this, to reduce delays, a new scheduling mode: a shorter TTI scheduling mode is provided. To be specific, a terminal is scheduled at a period of time less than one millisecond, for example, one slot or one symbol. In an LTE FDD network, using an example in which a terminal is scheduled at a period of one symbol, duration from a time point at which a base station sends data to the terminal to a time point at which the terminal feeds back a response is reduced to eight symbols. In other words, there is a delay of eight symbols from a time point at which the base station sends the data to a time point at which the base station learns whether the data is successfully sent, so that the delay is less than one millisecond. It can be learned that a delay time is dramatically reduced after the shorter TTI scheduling mode is applied.
When the foregoing two scheduling modes exist in a same LTE network, a radio resource waste is caused.